A lorry (British English) or truck (American English) is a motor vehicle designed to transport cargo. Trucks/lorries vary greatly in size, power and configuration, with the smallest being mechanically similar to an automobile. Commercial trucks/lorries can be very large and powerful, and may be configured to mount specialized equipment, such as in the case of fire trucks and concrete mixers and suction excavators. Modern trucks are powered by either gasoline or diesel engines, with the latter dominant in commercial applications.

In the United States, a commercial driver”s license is required to drive any type of commercial vehicle weighing 26,001 lbs (11,800 kg) or more.[3]

The United Kingdom and the rest of Europe now have common, yet complex rules (see European driving licence). As an overview, to drive a vehicle weighing more than 7,500 kilograms (16,535 lb) for commercial purposes requires a specialist licence (the type varies depending on the use of the vehicle and number of seats). For licences first acquired after 1997, that weight was reduced to 3,500 kilograms (7,716 lb), not including trailers.

In Australia, a truck driving license is required for any motor vehicle with a Gross Vehicle Mass (GVM) exceeding 4,500 kilograms (9,921 lb). The motor vehicles classes are further expanded as:

LR Light rigid: a rigid vehicle with a GVM of more than 4,500 kilograms (9,921 lb) but not more than 8,000 kilograms (17,637 lb). Any towed trailer must not weigh more than 9,000 kilograms (19,842 lb) GVM.

MR Medium rigid: a rigid vehicle with 2 axles and a GVM of more than 8,000 kilograms (17,637 lb). Any towed trailer must not weigh more than 9,000 kilograms (19,842 lb) GVM. Also includes vehicles in class ”LR”.

HR Heavy Rigid: a rigid vehicle with 3 or more axles and a GVM of more than 8,000 kilograms (17,637 lb)). Any towed trailer must not weigh more than 9,000 kilograms (19,842 lb)) GVM. Also includes articulated buses and vehicles in class ”MR”.

There is also a heavy vehicle transmission condition for a licence class HR, HC or MC test passed in a vehicle fitted with an automatic or synchromesh transmission, a driver’s licence will be restricted to vehicles of that class fitted with a synchromesh or automatic transmission . To have the condition removed, a person needs to pass a practical driving test in a vehicle with non synchromesh transmission (constant mesh or crash box).

In 2006, the U.S. trucking industry employed 1.8 million drivers of heavy trucks. There are around 5 million truck drivers in India.